Leg ulcers: diagnosing venous, arterial, and diabetic types in general practice

What a leg ulcer is

A leg ulcer is a full-thickness skin and soft-tissue wound below the knee that fails to heal within two weeks despite basic wound care. They affect approximately 1% of Australian adults at any given time, with prevalence rising sharply in older age groups and in people with diabetes, obesity, venous insufficiency, or peripheral arterial disease. They impose a significant burden — chronic pain, impaired mobility, recurrent hospitalisations, and in the worst cases limb loss — and are best managed through early, accurate diagnosis and a coordinated multidisciplinary approach.

The four main aetiological types are venous (~70%), arterial (~10%), mixed venous-arterial (~15%), and diabetic foot ulcer (~5%). A small proportion have other causes — pressure injury, neuropathic disease, vasculitis, pyoderma gangrenosum, malignancy, or infection. Accurate identification of type drives treatment: compression that heals a venous ulcer can harm an arterial one. This is why vascular assessment — including ankle-brachial pressure index (ABPI) measurement — is the mandatory first step before any wound management plan is initiated.

A. Core clinical — the AU general-practice framework

Differential diagnosis

The following features differentiate the common types on clinical examination:

Venous ulcers (~70%): Located over the medial gaiter area (the lower medial leg above the ankle). Margins are irregular and flat; the base is moist, often granulating or covered by yellowish slough. Surrounding skin shows the hallmarks of chronic venous insufficiency — haemosiderin staining (brown discolouration), lipodermatosclerosis (indurated thickened skin), atrophie blanche (pale scarred plaques), or venous eczema. Oedema is often present. Pulses are usually palpable.

Arterial ulcers (~10%): Located distally — on the toes, heel, dorsum of the foot, or areas subjected to friction. They appear punched-out with well-defined margins, a dry pale or necrotic base, and minimal exudate. The foot is cool; pulses are weak or absent; capillary refill is prolonged. Pain is prominent and characteristically worsens at night and with leg elevation.

Mixed venous-arterial (~15%): Features of both types on examination; common in older adults with both chronic venous insufficiency and peripheral arterial disease. Assessment is more complex and management requires specialist input.

Diabetic foot ulcer (~5%): Located at pressure points — most commonly the plantar surface under the metatarsal heads, heel, or over toe deformities. Neuropathy makes the wound often painless, allowing ulcers to develop unnoticed. The Charcot foot deformity (neuropathic joint destruction causing a rocker-bottom arch) is an advanced complication. Pulses may be present or absent depending on the degree of peripheral arterial disease.

Other causes to consider: pyoderma gangrenosum (painful ulcer with a violaceous undermined edge, associated with IBD, RA, or haematological malignancy — pathergy means debridement worsens it), Marjolin ulcer (squamous cell carcinoma arising in a chronic wound — biopsy any ulcer non-healing beyond 3 months), atypical mycobacterial infection (Buruli ulcer from Mycobacterium ulcerans is endemic in parts of tropical Queensland and Victoria), and cutaneous leishmaniasis in refugees from endemic regions.

Vascular assessment — mandatory before compression

Measuring ankle-brachial pressure index (ABPI) with a handheld Doppler before applying any compression bandaging is non-negotiable per Australian Wound Management Association (AWMA) guidelines and eTG:

• ABPI 0.9–1.3: normal arterial supply; multi-layer compression is safe.
• ABPI 0.8–0.9: mild arterial disease; modified compression is possible with caution and specialist review.
• ABPI 0.5–0.8: moderate arterial disease; seek vascular review before any compression.
• ABPI <0.5: severe or critical limb-threatening ischaemia — no compression; refer urgently to vascular surgery.
• ABPI ≥1.3: falsely elevated due to medial artery calcification (Mönckeberg sclerosis), common in diabetes and renal disease. Use toe-brachial index (TBI) instead — TBI <0.7 indicates significant arterial disease.

Full vascular and wound assessment includes:

• History of duration, pain pattern, comorbidities (diabetes, cardiac disease, smoking, autoimmune), and medications (corticosteroids, immunosuppressants, anticoagulants)
• Examination of the wound site, size, depth, base quality, exudate, and surrounding skin
• Lower limb pulses (femoral, popliteal, posterior tibial, dorsalis pedis)
• Sensation — 10 g monofilament and vibration (128 Hz tuning fork) for neuropathy
• Duplex ultrasound for venous reflux/patency and arterial stenosis
• Bloods — FBC, CRP, albumin, HbA1c, renal function, vitamin D

B. Evidence appraisal — the pillars of leg ulcer care

Multi-layer compression for venous ulcers: first-line

The strongest evidence in leg ulcer management is for graduated compression in venous disease. A Cochrane systematic review (O’Meara et al.) demonstrated that multi-layer compression bandaging heals approximately 50–70% of venous ulcers within 12 weeks compared with no compression. The compression creates a sustained external pressure gradient — highest at the ankle, decreasing proximally — that counteracts ambulatory venous hypertension.

Multi-layer compression consists of an inner padding layer, a cohesive or short-stretch bandage, and an outer layer achieving 30–40 mmHg at the ankle. Rapid Rhino–style and four-layer systems are standard. Compression hosiery (Class II, 18–25 mmHg, for prevention; Class III, 25–35 mmHg, post-healing) should be worn long-term after the ulcer heals to prevent recurrence. ABPI must be ≥0.8 before compression is initiated — this is the most important safety check in venous ulcer management.

Endovenous ablation for recurrence prevention

The EVRA trial (New England Journal of Medicine 2018) demonstrated that early endovenous thermal ablation (EVLA or radiofrequency ablation) of the incompetent superficial venous system significantly accelerates ulcer healing and reduces recurrence rates compared to deferred intervention. Patients with confirmed superficial venous reflux and a venous ulcer should be referred to vascular surgery or an endovenous ablation service for consideration of early intervention alongside compression.

Off-loading for diabetic foot ulcers: critical principle

Off-loading — removing pressure from the wound site — is the single most important principle for healing a neuropathic diabetic foot ulcer. IWGDF 2023 guidelines recommend the total contact cast (TCC) as the gold standard; it cannot be removed by the patient and maintains continuous off-loading. A well-fitted removable cast walker or boot is the next-best option. Standard footwear is not off-loading — plantar ulcers will not heal if weight-bearing continues normally.

Vascular referral for arterial disease

Any ulcer with an ABPI below 0.5, rest pain, tissue loss on the foot, or rapidly expanding necrosis represents critical limb-threatening ischaemia and requires same-day vascular surgery referral for assessment of revascularisation (endovascular angioplasty/stenting or surgical bypass). NICE CG147 and ESVS 2024 guidelines both emphasise that revascularisation is limb-saving in critical ischaemia. Concurrent cardiovascular risk reduction — smoking cessation (the most important modifiable factor), statin therapy, antiplatelet therapy, and blood pressure control — is mandatory.

C. Infection and antibiotic stewardship

All chronic leg ulcers are colonised by bacteria. Colonisation is normal and does not require antibiotic treatment. Clinical infection — the only indication for antibiotics — is defined by localised signs (increasing pain, periulcer erythema >2 cm, warmth, swelling, purulence) or systemic signs (fever, raised white cell count, CRP elevation). IDSA 2012 and IWGDF 2023 both emphasise selective antibiotic prescribing to avoid resistance. Do not swab a wound without clinical signs of infection — the result will reflect colonisation and may prompt inappropriate prescribing.

Diabetic foot infection grading (IDSA/IWGDF):

• Mild: superficial infection, periulcer erythema ≤2 cm; oral antibiotics (cephalexin or di/flucloxacillin first-line; clindamycin if penicillin allergy; TMP-SMX if MRSA risk).
• Moderate: erythema >2 cm, deeper tissue involvement, or lymphangitis; oral or IV antibiotics depending on severity; consider hospital assessment.
• Severe: systemic signs (fever, hypotension, tachycardia); admit; IV antibiotics; surgical debridement; multidisciplinary team review.
• Osteomyelitis: probe-to-bone test positive (positive predictive value ~90%); MRI is the investigation of choice; bone biopsy for culture-guided therapy; 4–6 weeks of targeted antibiotics ± surgical debridement or resection.

Wound debridement — removal of slough, necrotic tissue, and biofilm to expose granulating base — is a core wound care principle. Sharp debridement by an experienced wound nurse or podiatrist accelerates healing. In arterial ulcers, debridement must be approached cautiously — do not disturb stable dry eschar over ischaemic tissue without vascular assessment.

D. Australian operations

General practice coordination

The RACGP frames chronic leg ulcer management as a general practice-coordinated multidisciplinary process. The GP’s role encompasses assessment, ABPI measurement, antibiotic prescribing, referral coordination, care plan management, and psychosocial support for a condition that profoundly affects quality of life.

MBS item numbers (via MBS Online):

• Items 23 / 36 / 44 — GP consultation levels
• Item 715 — ATSI Health Assessment (includes annual diabetes foot screen)
• Item 707 — 75+ Health Assessment
• Item 10961 — podiatry under GP-coordinated EPC allied health plan (5 allied health visits/year combined; high-risk diabetic foot has expanded access)
• Item 10960 — wound nurse, OT, or physiotherapist under EPC
• Item 10954 — dietitian under EPC
• Item 55700 — duplex ultrasound of venous or arterial system
• Item 55890 — MRI lower limb
• Item 56401 — CT angiography
• Item 32500 — venous endovenous ablation (specialist)
• GPCCMP items 965 / 967 — central for complex chronic wound care planning; replaced items 721/723/732 from 1 July 2025

PBS prescribing:

• PBS General Schedule covers antibiotics (cephalexin, di/flucloxacillin, clindamycin, amoxicillin-clavulanic acid, metronidazole, doxycycline, TMP-SMX), statins, antiplatelets (aspirin, clopidogrel), and pentoxifylline (adjunct for venous ulcers; modest evidence).
• Wound dressings are not PBS-listed for community patients in most cases — patients pay privately or access through state-funded community nursing schemes. DVA Gold/White Card covers wound care, podiatry, and equipment for eligible veterans.
• Compression hosiery is not PBS-listed; cost is private or via some private health insurance.

Multidisciplinary team: Effective leg ulcer care almost always requires a team: GP (coordinator), vascular surgeon (ablation or revascularisation), podiatrist (high-risk foot specialist), wound nurse or community nurse (dressings), endocrinologist or diabetes physician (glycaemic optimisation), infectious disease specialist (osteomyelitis), dietitian (nutrition), and social work (home support). Diabetes Feet Australia maintains a directory of high-risk foot clinics.

Australian patient resources:

• HealthDirect — Leg ulcers
• Better Health Channel — Leg ulcers
• Wounds Australia — peak body for wound care professionals and patients
• Diabetes Feet Australia — diabetic foot resources
• AWMA — Australian Wound Management Association

E. Special populations

Older adults: Leg ulcers are most prevalent in adults over 65, in whom multiple comorbidities — heart failure, chronic kidney disease, immobility, frailty, polypharmacy — complicate both wound healing and management. Venous oedema worsens with heart failure; diuretic optimisation alongside compression supports both. Falls risk is heightened; physiotherapy and home environment assessment are valuable. The psychosocial burden of chronic leg ulcers in older adults is substantial — isolation, depression, and carer burnout are common and should be addressed as part of a GPCCMP.

People with diabetes: Diabetes drives both neuropathy and peripheral arterial disease, creating the conditions for foot ulceration. Annual diabetic foot screening (item 715 ATSI or item 707 for 75+, and standard GP review using the IWGDF risk classification) identifies high-risk feet before ulceration occurs. Referral to a high-risk foot clinic via Diabetes Feet Australia is appropriate for IWGDF category 2 or 3 feet. Charcot neuroarthropathy — destructive neuropathic joint disease causing a rocker-bottom deformity — is a medical emergency requiring urgent off-loading and orthopaedic input.

Aboriginal and Torres Strait Islander peoples: ATSI peoples carry disproportionately high burdens of type 2 diabetes, peripheral arterial disease, and chronic wound complications. Item 715 enables structured annual health assessments including foot screening. Cultural safety, community-based wound care nursing, and referral pathways adapted to remote and regional settings are important considerations.

Refugees and migrants from endemic regions: Buruli ulcer (Mycobacterium ulcerans) is endemic in parts of tropical north Queensland and Gippsland in Victoria, and also in parts of sub-Saharan Africa and South-East Asia. The ulcer has a necrotic undermining edge and is characteristically painless. Diagnosis is by PCR on wound swab or tissue; rifampicin-based treatment is curative. Cutaneous leishmaniasis presents with a painless nodule that ulcerates in travellers and refugees from Middle Eastern, African, or South American endemic regions.

When to escalate

Refer to vascular surgery urgently if:

• ABPI <0.5, rest pain, or advancing foot gangrene — critical limb-threatening ischaemia
• ABPI 0.5–0.8 and the ulcer is not improving — specialist vascular assessment needed before compression
• Non-healing mixed ulcer despite optimised compression and wound care

Refer to ENT or wound specialist if:

• Ulcer has not improved after 12 weeks of appropriate first-line management
• Pyoderma gangrenosum suspected — do not debride; refer to dermatology or rheumatology
• Any chronic non-healing ulcer present for more than 3 months — biopsy mandatory to exclude Marjolin ulcer (squamous cell carcinoma)

Refer to infectious disease or orthopaedics if:

• Osteomyelitis confirmed or strongly suspected on probe-to-bone or MRI
• Severe or systemic diabetic foot infection requiring IV antibiotics and possible surgical debridement
• Suspected Buruli ulcer, atypical mycobacterial infection, or cutaneous leishmaniasis

Refer to podiatry (via EPC, item 10961) for all patients with diabetes and an active foot wound — this is a standard-of-care referral, not an escalation. Diabetes Feet Australia and AWMA maintain referral directories.

What this article is and is not

This is general health information drawn from current Australian guidelines — Therapeutic Guidelines (eTG), AWMA Venous Leg Ulcer Guidelines, Diabetes Feet Australia, RACGP, Wounds Australia — and major international guidelines (IWGDF 2023, IDSA 2012, ESVS 2024, NICE CG147, Cochrane). It is not personal medical advice and does not create a doctor–patient relationship. Leg ulcer management is highly individual — decisions about ABPI thresholds, compression choice, antibiotic prescribing, vascular referral, and care planning are made in consultation with your GP and multidisciplinary team.

For consumer information: HealthDirect — Leg ulcers, Better Health Channel, Wounds Australia, Diabetes Feet Australia.

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Sources cited

1. Australian Wound Management Association (AWMA) — Venous Leg Ulcer Guidelines
2. Diabetes Feet Australia — Australian Diabetes-Related Foot Disease Guidelines 2022
3. Cochrane — Compression for venous leg ulcers (O’Meara et al.)
4. IWGDF 2023 — International Working Group on the Diabetic Foot
5. IDSA 2012 — Diabetic foot infections (Lipsky et al.)
6. ESVS 2024 — Chronic Venous Disease Clinical Practice Guidelines
7. NICE CG147 — Lower limb peripheral arterial disease
8. Therapeutic Guidelines (eTG) — Leg ulcers and wound care
9. Wounds Australia — Pan-Pacific Clinical Practice Guideline for Pressure Injury 2019
10. RACGP
11. HealthDirect — Leg ulcers
12. MBS Online
13. PBS Australia
14. Better Health Channel — Leg ulcers